Macrobenthic community structure of soft-bottom sediments at the Belgian Continental Shelf

摘要: Within the frame of different research projects, a large number sites at Belgian Continental Shelf (BCS) have been sampled for macrobenthos between 1994 and 2000. These samples cover diverse range habitats: from sandy beaches to open sea, gullies sandbanks tops sandbanks, clay coarse sediments. To investigate large-scale spatial distribution Shelf, data all these projects—728 samples—were combined analysed. By means several multivariate techniques, 10 sample groups with similar macrobenthic assemblage structure were distinguished. Each group is found in particular physico-chemical environment has specific species composition. Four differ drastically, both habitat composition, are considered represent four communities: (1) muddy fine sand Abra alba–Mysella bidentata community characterized by high densities diversity; (2) Nephtys cirrosa occurs well-sorted sediments low (3) very diversity typify Ophelia limacina–Glycera lapidum community, which (4) Eurydice pulchra–Scolelepis squamata typical upper intertidal zone beaches. communities not isolated each other, but linked through six transitional assemblages. The transition A. alba–M. N. reduction mud content dominated Magelona johnstoni. O. limacina–G. distinctive decreasing coincides gradual medium From E. pulchra–S. assemblages related subtidal found. or was over along onshore–offshore gradient, types can be discerned: almost restricted near-shore area, possible wider distribution; distributed full gradient; area beach environment. pattern on BCS follows this division, rich poor only more offshore. patterns type, distinguished median grain size content.